Physicochemical Confinement Effect Enables High-Performing Zinc-Iodine Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Zinc-iodine batteries offer advantages like aqueous electrolytes and safer zinc anodes.
• Performance limitations include the polyiodide shuttle effect and an unclear iodine redox mechanism.

Purpose of the Study:

• To enhance the performance of zinc-iodine batteries by addressing the polyiodide shuttle and improving the iodine redox mechanism.
• To develop a novel catalyst using single iron atoms embedded in porous carbon with a metal-nitrogen-carbon structure.

Main Methods:

• Incorporation of single iron atoms into a porous carbon matrix with a metal-nitrogen-carbon atomic bridging structure.
• Utilized in-situ experimental characterization and theoretical calculations to understand the catalytic mechanism.
• Fabrication and testing of zinc-iodine battery prototypes.

Main Results:

• The metal-nitrogen-carbon structure effectively confined polyiodide species and catalyzed the electro-redox conversion of iodine.
• Enhanced electronic conductivity and modulated electronic properties of carbon by the catalyst.
• Achieved high capacity and good cycling stability in the zinc-iodine batteries.

Conclusions:

• Single atom catalysis within a metal-nitrogen-carbon framework is a viable strategy to overcome limitations in zinc-iodine batteries.
• Physicochemical confinement and enhanced electrocatalytic activity are crucial for high-performing zinc-iodine batteries.
• This approach provides fundamental insights for designing advanced catalysts for energy storage applications.